program Project2;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
  fin : textFile;
  mass : array of integer;
  mass1 : array of integer;
  i, n, s, m : integer;
  flag:boolean;
begin

  assignfile (fin, 'input.txt');
  reset (fin);
  flag:=false;
  readln(fin, n);
  setlength (mass, n);
  setlength (mass1, n);
  for i := 0 to n-1 do
  begin
    read (fin, mass[i]);
    readln (fin, mass1[i]);
  end;
  s:=0;
  mass[n]:=mass[0];
  mass1[n]:=mass1[0];
  mass[n+1]:=mass[1];
  mass1[n+1]:=mass1[1];
  s:=0;
  for i:= 1 to n-1 do
  begin
    m:=s;
    s:=mass[i-1]*mass1[i]-mass[i]*mass1[i-1]+mass[i]*mass1[i+1]-mass[i+1]*mass1[i]+mass[i+1]*mass1[i-1]-mass[i-1]*mass1[i+1];
    if (m*s<0) then
    begin
      Flag:=true;
      break;
    end;
  end;
  if (flag) then
    writeln ('Your polygon is not convex.')
  else
    writeln ('Your polygon is convex.');
  closefile (fin);
  readln;
end.
